Multiple-needle sewing machine



Feb- 3, 1959 G. QUlTTr-:R

MULTIPLE-NEEDLE SEWING MACHINE Filed Aug. 23, 1956 2 Sheets-Sheet lAGENT Feb. 3, 1959 G, QUITTER l 2,871,810

MULTIPLE-NEEDLE SEWING MACHINE Filed Aug. 25, 195e\ l 2 sheets-sheet 2AGEA/7' United States Patent() MULTIPLE-NEEDLE SEWING MACHINE GerhardQuitter, Bielefeld, Germany, assignor to DurkoppwerkeAktiengesellschaft, Bielefeld, Germany, a corporation of GermanyApplication August 23, 1956, Serial No. 605,863 Claims priority,application Germany August 25, 1955 Claims. (Cl. 112-221) The presentinvention relates to sewing machines having two or more needles whichcan be selectively taken Into use and put out of commission by acoupling mechanism adapted to impart up-and-down reciprocating movementto only one needle at a time.

Machines of this character, which are used principally for makingangularly extending seams, have heretofore been built only forrelatively low speeds, such as about 1300 stitches per minute; thereason for this limitation has been the complexity of the couplingmechanism which had to be of sturdy and, hence, bulky construction inorder to withstand the stresses and strains of frequent coupling anddecoupling.

An object of this invention is to provide an improved coupling mechanismfor the purpose set forth whose reciprocating components are of lightweight so as to enable high-speed operation, e. g. at a rate of about3000 stitches per minute, with a machine so equipped.

Another object of this invention is to provide dependable and easilyoperable means for positively coupling a needle bar or similar implementwith a continuously moving driving member .and for just as positivelycoupling such implement with a stationary retaining member afterdecoupling it from the drive member, thereby preventing frictionalentrainment or-accidental manual displacement of the inactivatedimplement.

A more specic object of this` invention isto provide novel and improvedmeans for selectively coupling a pair of nested tubular members for thepositive entrainment of one by the other.

A feature of' the present invention resides in the pro-` visionof atubular needle bar received in an axially reciprocating sleeve andsurrounding, in turn, an elongated, spring-loaded control member. Seatedin a wall aperture of the needle bar is a coupling element adapted to becammed in or out by the outer sleeve and by the inner control member,respectively. Inuits outwardly cammed position, into which it is urgedby the spring-loaded control member, the coupling element positivelyengages the outer sleeve and causes the needle bar to be entrained bythe latter; to decouple the needle bar from the sleeve, an abutmentsisplaced in the path of a projecting extremity of the control member s oas to cause relative displacement between this member and the needlebar, such displacement freeing the coupling element for inwardV cammingby the sleeve and disenga'ging the latter from the needle bar. In orderto prevent the needle bar from following thel sleeve in its continuingreciprocation, there is preferably provided a second, similar couplingelement co-operating with the control member so as to be cammedoutwardly by the said relative displacement thereof, thisl i secondcoupling element thereupon engaging another, stationary sleeve wherebythe needle bar becomes immobilized. This conditionV obtains until theabutment is 1 2,871,810 Patented Feb. 3, 1959 and the first couplingelement is cammed outwardly to' re-engage the moving sleeve, whereuponentrainment of the needle bar by the last-mentioned sleeve is resumed.

In order to minimize the risk of jamming, there are preferably provideda plurality of coupling elements in angularly oiset positions for boththe moving sleeve and the stationary sleeve. A particularly simple formof coupling element is a steel ball of a radius approximately equal tothe wall thickness of the needle bar.

'The above and other objects, features and advantages ofthe inventionwill become more fully apparent from the following detailed descriptionof a preferred embodimolded head 2. Seated in this head are two tubularVneedle bars 3 and 4 guided for vertical reciprocating movement in aneedle guide 5. A cross-head 6, whose crank pin 7 is connected with asuitable driving mechanism not shown, reciprocates in the mannerindicated by the arrow whenever the driving mechanism is energized.

The needle guide` 5 is swingable about an axle 9 which is lodged in thehead 2 and secured to it by a setscrew 8.

A collar 10, provided with` a-projection 10', is slidably mounted o-naxle 9and is engaged by astud 11 whoseKA shank is fastened to a rod 12by a setscrew 13. The

upper part of the needle guide providesgenough clearance?.

around collar 10 to enable the projection 10 thereof to be aligned witheither of the two needle bars 3,4 o1-` to assume an intermediateposition therebetween. In/theI` drawing the Aprojection 10 is alignedwith needle barili;

which means that this needle bar is decoupled, aswillbecome clear lateron; in the neutral intermediate position both needle bars are positivelycoupled with the cross-head 6 for entrainment thereby,v

A shift lever 14 is secured to a shaft 15 which is rotatably lodged in alug 16 integral with machine framegl.:V The `other extremity of shaft 15carries a second lever 17 f with laterally projecting ball-head stud 18Awhich isre-- ceived in a socket 29 of a pitman 30. Thelatter, which" isof adjustable length, terminates in another universal.

joint comprising a socket 28l which receivesV a ball-head stud 27threadedly secured to a rearward extension of a switch box housing 19.'This housing, which is pivotable about a stud shaft 26 rising frommachine head 2, forms two pairs of aligned piston cylinders closed byscrew caps 22, 23 and 5.3; 54, respectively.

a pin 55, txedly held in head 2, in a manner tending to keep housing 19centered so as to position the 10 between the needle bars 3 and 4. p

Since the two needle bars and their mountings .are

projection identical, only bar 4 will be described in detail.' This baris provided with a plurality of angularly spaced radial apertures 33,preferably three (only two shown), containing each a steel ball 31 whosediameter exceeds the The inst-mentioned piston cylinders containplungers 24 and 25, respectively,- whose enlarged inner ends bear uponopposite extremities of rod 12 and whose outer ends pass through thecen- Walli thickness of the tubular needle bar so that this ballprojects either outwardly from the bar or into theV iuterior thereof. Asecond set of similar apertures 47, located farther down on bar 4, forma seat for three additional steelballs 44. An elongated control rod 39,axially traversing the bar 4 as well as a screw cap 40 at the upper endthereof, has its lower end guided in a bushing 42 serving as the loweranchor for a compression spring 43; this spring bears upon a shoulder 39of rodk 39, so as to urge the latter upwardly. A short piston rod 7-1connects bushing 42 with a frusto-conical cam member 32 which is held atthe level of balls 31 by a spacer rod 37; the lower end of this rod,shown eccentrically positioned so as not to interfere with the inwarddisplacement of balls 44, is supported by a compression spring 36. Asecond frusto-conical cam member L26 is slidably heldlon rod 37 abovethe eccentric lower portion thereof, being urged downwardly by acompression spring 35 engaging the enlarged, screwed-on head of thisrod. The length of spacer rod 37 is such that cam member 46, positionedfor engagement with steel balls 44, will be out of contact with theseballs while cam member 32 engages the steel balls 31, and vice versa.

The cross-head 6 forms a sleeve around each of the two needle bars 3 and4. A conical recess 34 at the lower end of the sleeve surrounding bar 4is adapted to cam inwardly the steel balls 31 in the absence ofinterference by conical member 32; in similar manner the sleevesurrounding bar 3 is provided with a conical recess 134 adapted to exertinward camming action upon the corresponding balls 131 thereof.

The lower portion of needle guide 5 is provided with two bushings 48 and148 respectively surrounding the needle bars 4 and 3. The upper end ofbushing 48 has a conical recess 48 adapted to exert inward cammingaction upon the steel balls 44 in the absence of interference by conicalmember 46; in similar manner the bushing 148 is provided with a conicalrecess 148' for the inward camming of the steel balls 144 in needle bar3.

The displacement between the needle bars 3 and 4 relative to thecross-head 6 and to the needle guide 5 is limited by two collars 138 and38 respectively carried by these bars. These collars are formed withexternal channels 138 and 38 respectively, as seen in Fig. 2, into whichcan penetrate pins 61 and 62 carried by crosshead 6 and pins 63 and 64carried by needle guide 5. In this manner the needle bars 3 and 4 aresecured against rotation. The needles 68 and 168 are mounted on holders65 and 165 whose shanks are received in the lower extremities of needlebars 4 and 3, respectively, with a certain amount of axial play providedby a setscrew 66 Whose head plays in a slot 67 of the needle bar asparticularly illustrated for bar 3. The dimensioning ofV cross-head 6and of guide 5 is such that the balls 31, 131 and 44, 144 will not befree, in any position of the needle bars, to drop out of theirapertures.

Secured to the machine frame 1 by a screw S8 is a at spring 57 whoselower end engages the shank of a knob 59 received in a slot 56 in thelower part of shift lever 14. This lever also carries a stud 60 adaptedto block the lever in either of two limiting positions by its engagementwith an edge of spring 57. To release the shift lever it is necessary topress the knob 59, whereupon the action of springs 49 and 50 in housing19 (Fig. 3) centers the entire switching assembly 14, 17, 19 and 10 soas to place abutment 10' in its neutral position. A direct transitionfrom one shifting position to the other is thereby prevented, thusinsuring that the hitherto idle needle is fully actuated before theother needle is taken out of service.

The operation of the improved coupling machanism described' above willnow be outlined in detail.

In the position shown in the drawing, needle'168 is elevated andinactive while needle 68 follows the movements of cross-head 6. This isso because the balls 3l are cammed' outwardly by cone 32 and bear uponthe conical recess 34 of cross-head 6 which at the same time is engagedfrom above by the collar 38, needle bar 4 being thus in rm clampingengagement with the crosshead. As the needle bar reciprocates, itperiodically reaches an upper dead-center position in which the pro*jecting extremity of control rod 39 extends above the level. of abutment10 which at this time is in contact with the corresponding rod 139 ofneedle bar 3 and does not interfere with the operation of needle bar 4.

Let us now assume that the operato-r, desiring to immobilize needle 68and to activate needle 168, has released lever 14 by pressing upon knob59 and has swung this lever Icounter-clockwise (as viewed in Fig. l)into its other limiting position. lf this maneuver happened to occur atthe instance when cross-head 6 was in its upper dead-center position,collar extension 10 was momentarily prevented by the rod 39' fromoccupying its righti-hand position, rod 12 remained stationary andspring 2t? was compressed by the counter-clockwise swing of housing 19as viewed in Fig. 3. (Had the shift occurred from right to left, spring21 would have been compressed.) Upon the next descent of rod 39 thespring 28 releases its stored energy and shifts abutment 10 intovertical alignment with rod' 39. At the completion of the next ascent,rod 39 finds itself blocked while needle bar 4 continues to rise againstthe force of spring 35 which, yielding, allows the cone 32 to disengageto coupling balls 31. At the same time the cone 46 will be resilientlyarrested, through thev intermediary of compression spring 35, in aposition in which it will cam the balls 44 outwardly and into contactwith conical recess 4S at the instant when the bar 4 reaches the upperlimit of its travel; the expansive force of spring 35 and the cammingAaction of balls 44 imparts a slight additional upward push to needle bar4 whereby the latter is driven beyond dead center and collar 38 is madeto engage the upper portion of the needle guide 5, thus positivelyclamping the bar 4 to the stationary needle guide. The last-mentionedupward movement of the needle bar, occurring with the cross-head 6virtually at standstill, results in the inward displacement of couplingballs 31 by the camming action of conical recess 34, these balls thusbeing retracted inside needle bar 4 so as no longer to interfere withthe displacement of crosshead 6 relative to this bar. Any lowering ofbar 4 through gravity or frictional entrainment is now impossible.

Meanwhile, the removal of abutment 10' from the top of rod 139 hasallowed spring 136 within bar 3 to expand and to raise the cone 146 outof engagement with steel balls 144, at the same time lifting the cone132 into contact with balls 131 through the intermediary of spring 135.As soon as the cross-head 6 again reaches its upper limiting position,it releases the balls 131 for outward movement and the residualexpansion of spring 135 causes these balls, in camming engagement withconical recess 134, to drive the needle bar 3 slightly lower untilcollar 138 comes to rest upon cross-head 6 and cornpletes the clampingaction. The slight lowering of needle bar 3 also causes the conical seat148' to cam inward the balls 144 so that relative motion between thisneedle bar and the guide 5 may now freely take place.

It will thus be seen that there has been provided an arrangement which,by the Simple positioning of an abutment 10 in or out of the path ofcontrol member 39 or 139, the corresponding needle bar is firmly clampedto either a moving driving member 6 or a stationary guide or support 5.The coupling elements 31, 44 and associated parts are of smalldimensions and do not necessitate an undue enlargement of the needlebars 3, 4 or of the cross-head 6. The spacing of the coupling elementsand of the associated cam members 32, 46 has been so selected that theballs 44' will be able to move fully inwardly only after the balls 31have positively lockedthe needle bar to the cross-head so that nouncontrolled descent of the needle bar can take place; also, the slightadditional upward movement of the needle bar'beyond dead center,resulting from the camming engagement between the balls 44 and theconical seat formation 48 as has been described, serves 'to raise thecollar 38 above its normal upper limiting position so that it will notbe periodically impinged upon by the reciprocating` crosshead, wherebywear will be reduced. Apart from these advantages, however, it should beunderstood that some of the features of the invention 4may be embodiedin systems using means other than those specifically illustrated forblocking the descent of the, decoupled needle bar and/or for allowingthe coupling elements 31 or 131 to recede into an inoperative positionwithin the bar, and

'that in general the invention may be modified in various ways withoutdeparting from the spirit and the scope of the appended claims.Naturally, any number of needle bars may be selectively actuated,individually` or simultaneously, by the mechanism herein disclosed or by`its equivalents apparent Vto persons'skilled in the art.

What is claimed is:

l. In a sewing machine, in combination,ia reciprocable sewing implement,continuously movable actuating means and mechanism for selectivelycoupling said implement with said actuating means; said mechanismcomprising an axially reciprocable tubular member operatively connectedwith said implement, an axially reciprocable sleeve member operativelyconnected with said actuating mechanism and surrounding said tubularmember with freedom of relative axial motion, said tubular member havinga wall with an aperture and radially displaceable coupling means in saidaperture, cam means within said `tubular member axiallyl shiftablerelatively thereto for moving said coupling meansVA outwardly throughsaid Wall and into Operative engagement with said sleeve member, therebyoperatively coupling said tubular member with said ,sleeve member forentrainment thereby, resilient means 'internally anchored to saidtubular member and axially bearing upon said cam means in a sense urgingthe latter into outward-camming action upon said coupling means, anaxially displaceable control element operatively connected with said cammeans and projecting from an end' of said tubular member, abutment meansadjacent said end of said tubular member selectively positionable in thepath of said control element for axially displacing the latter alongwith said cam means relatively to said tubular member against the actionof said resilient means upon movement of said tubular member in apredetermined axial direction, thereby releasing said tubular memberfrom entrainment by said sleeve member, and blocking means adjacent saidtubular member engageable therewith for arresting the return movement ofsaid tubular member.

2. The combination according to claim l, wherein said coupling meanscomprises a spherical element of a diameter greater than the wallthickness of said tubular member.

3. The combination according to claim 2, wherein said coupling meanscomprises-a plurality of angularly spaced steel balls. v

4. The combination according to claim 1, wherein said sleeve member hasan extremity engageable with said coupling means and provided with aformation adapted to cam .said coupling means inwardly in the arrestedcondltion of said tubular member.

5. The combination according to claim 4, comprising stop means on saidtubular member facing the other extremity of said sleeve member andpositioned to be brought into contact with said other extremity by acamming engagement between said formation and saidcoupling means uponoutward movement of the latter, whereby said sleeve member is positivelylocked to said tubular member:

6. The combination according to claim 1, comprising a manuallyshiftable'operating member for said 'abutment means and a resilient linkbetween said operating member and said abutment means, said linkenabling said abutment means to occupy a position in the path of saidcontrol element after the latter has withdrawn from a limiting position.

7. The combination according to claim l, wherein said blocking meanscomprises a second, stationary sleeve member surrounding said tubularmember, said tubular memberbeing provided with a second aperture in itswall and with second coupling means in said second aperture engageablewith said second sleeve member, further -comprising second cam meanswithin said tubular member axially shiftable relatively thereto formoving said second 'coupling means outwardly through said `wall and intooperative engagement with said second sleeve member, thereby xedlyanchoring said tubular member to said second sleeve member, andconnecting means between said two cam means for renderingsaid second cammeans eiective upon disengagement of the first-mentioned cam means fromthe rst-mentionedcoupling means.

8. The combination `according to claim 7, wherein said second sleevemember has an extremity engageable with said second coupling means andprovided with a formation adapted to cam said second coupling meansinwardly upon entrainment of said further member by the rstmentionedsleeve member.

9. The combination according to claim 8, comprising stop means on saidtubular member facing the other extremity of said second sleeve memberand positioned to be brought into contact with the last-mentionedextremity by a camming engagement between said formation and said secondcoupling means upon outward movement of the latter, whereby `said secondsleeve member is positively locked to said tubular member.

l0. The combinationA according to claim 7, wherein said connecting meansincludes a resilient link.

1l. ln a sewing machine, in combination, a plurality of parallel needlebars, stationary guide means for said needle bars, said bars beingaxially reciprocable in said guide means, a drive member reciprocablerelatively to said guide means in axial direction of said needle bars,rst and second Icoupling means on each of said needle bars radiallydisplaceable thereon for selective engagement respectively with saiddrive member and with said guide means, a

control element on each of said needle bars for respectively operatingthe irst and the second coupling means thereof in a first and in asecond relative axial position, said control element being axiallyshiftable relatively to its needle bar for coupling the latter witheither said drive member or said guide means by outwardly displacingsaid rst and said second coupling means in said lirst and said secondaxial position, respectively, and abutment means on said guide meanspositionable in the path of any of said control elements duringentrainment of the respective needle bars by said drive member fordecoupling an entrained needle bar from said drive member by relativelyshifting its control element from said first into said second axialposition.

l2. The combination according to claim 11, further comprising resilientmeans anchored to each needle bar and bearing upon its control elementfor restoring the latter to said first axial position upon removal ofsaid abutment means from its path.

13. The combination according to claim 12, wherein said needle bars aresubstantially vertical and provided with needle-holding means at theirlower ends, said abutment means being positionable for engagement bysaid control elements upon said needle bars approaching an upperlimiting position.

14.' The combination according to claim 12, further comprising springmeans 0n said guide means tending to maintain said abutment means in aneutral position out of line with said control elements, and shift meanson said guide'means for displacingA said abutment means against theaction of said spring means.

15. The combination according to claimy 14, further comprising delaymeans on said guide means engageable withy said shiftmeans fortemporarily arresting the latter in an intermediate position,correspondingto the neutral position of said abutment means, uponoperation of said shift means to displace said abutment means fromalignment with one'to alignment withanother of said control elements.

16. The combination according to claim 15, wherein said delay meanscomprises videtent means effective to lock said shift means in any ofseveral operative positions and manually operable release meansforinactivating said detent means and enabling said spring means to movesaid shift means into said intermediate position.

1-7. The combination according to claim 11, wherein said drive memberand said guide means form axially spaced sleeves about said needle bars,Asaid bars being provided with shoulders intermediate said sleeves forlimiting the displacement of said needle bars relative to said guidemeans and to said drive member.

18. The combination according to claim 17, wherein said needle bars andsaid sleeves are cylindrical, said shoulders being formed by collars onsaid needle bars having eccentric channels, said drive member and saidguide means being provided with projections adapted to enter saidchannels in a state of entrainment and at standstill of said needlebars, respectively, thereby maintaining said needle bars inpredetermined angular positions.

19. A coupling mechanism for sewing-machine needles and the like,comprising an axially reciprocable rst sleeve member, a stationarysecond sleeve member, a tubular member surrounded by both of said sleevemembers with freedom of relative axial motion, said tubular memberhaving any apertured wall, first andl second coupling means axiallyspaced insaid wall and radially displaceable therethrough for selectiveengagement with said first and said second sleevemember, respectively, acontrol element for both of said coupling. means extending within saidtubular member and projecting from one end thereof with freedom ofrelativel axial motion, said control element operatively engaging saidfirst coupling means in a first relative axial position operativelyengaging said second coupling means in a second relative axial positionfor radial movement thereof into coupling engagement respectively withsaid first and with said second sleeve member, abutment means adjacentsaid one endV of said tubular member selectively positionable in thepath of said control element during entrainrnent of said tubular memberby said first sleeve member for shifting said control element relativelylto said tubular member from said first into said second axial position,thereby decoupling said tubular member from said first sleeve member andcoupling it with said second sleeve member, and drive means forrcciprocating said first sleeve member.

20. A coupling mechanism according to claim 19, further comprisingspring means anchored to said tubular member and bearing upon saidcontrol element for restoring the latter to said rst axial position uponremoval of said abutment means from the path of said control element,thereby decoupling, said tubular member from said second sleeve memberand coupling it with said first sleeve member for entrainment thereby.

References Cited in the file of this patent UNITED STATES PATENTS1,379,468 Matson May 24, 1921 1,676,853 Brase July 10, 1928 2,772,578Kling Dec. 4, 1956

